Mortgage

When you get a mortgage on a house, you are essentially shorting the currency that you bought that house in.

The only thing of real value involved in a mortgage in the asset posed as collateral.

A mortgage agreement has monetary value, backed by both the trust of the mortgaged individual and the asset that the mortgage is on.

A mortgage is an I.O.U, and in a sense equivalent to money, since it is portable, exchangeable and saleable.

A mortgage is distinct from a typical borrowing scenario, such as borrowing a hammer from a neighbor. In the financial world, the bank lets us pay with money which it doesn't have.

If the bank didn't have the mortgage in their possession, there would be no money to lend.